To be divisible by both 4 and 5, the number has to be divisible by 20. Therefore, there are 12 numbers between 1 and 240, inclusive, which are divisible by 4 and 5: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240.
All whole numbers are divisible by 1. Numbers are divisible by 2 if they end in 2, 4, 6, 8 or 0. Numbers are divisible by 3 if the sum of their digits is divisible by 3. Numbers are divisible by 4 if the last two digits of the number are divisible by 4. Numbers are divisible by 5 if the last digit of the number is either 5 or 0. Numbers are divisible by 6 if they are divisible by 2 and 3. Numbers are divisible by 9 if the sum of their digits is equal to 9 or a multiple of 9. Numbers are divisible by 10 if the last digit of the number is 0.
40
125 different 4 digits numbers. To be divisible by 4, the last two digits must be divisible by 4, which means they must be: 12, 24, 32, 44 or 52 - 5 possible choices. For each of these there are 5 choices for the first digit and 5 for the second, meaning: total = 5 x 5 x 5 = 125
the lowest number divisalbe by all of them is 6060/2=3060/3=2060/4=1560/5=12
Numbers for which the sum of the digits is divisible by 9. This is also true for 3. There are other divisibility/multiple tests for other numbers (e.g., numbers that are divisible by 5 end in 5 or 0; numbers whose last two digits are divisible by 4 are divisible by 4)
To be divisible by both 4 and 5, the number has to be divisible by 20. Therefore, there are 12 numbers between 1 and 240, inclusive, which are divisible by 4 and 5: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240.
...-20, -16, -12, -8, -4, 0, 4, 8, 12, 16, 20,....
They are divisible by 2, 3, 4, 5, 6, 10, 12, 15, 30 and 60 at least.
Divisible by 5
Numbers that are divisible by both 4 and 5 are multiples of the least common multiple of 4 and 5, which is 20. Therefore, numbers that are divisible by 4 and 5 are multiples of 20. In other words, any number that can be expressed as 20 multiplied by an integer (e.g., 20, 40, 60, 80, etc.) is divisible by both 4 and 5.
There are infinitely many numbers divisible by 5 and 4. 680 is one of them.
All whole numbers are divisible by 1. Numbers are divisible by 2 if they end in 2, 4, 6, 8 or 0. Numbers are divisible by 3 if the sum of their digits is divisible by 3. Numbers are divisible by 4 if the last two digits of the number are divisible by 4. Numbers are divisible by 5 if the last digit of the number is either 5 or 0. Numbers are divisible by 6 if they are divisible by 2 and 3. Numbers are divisible by 9 if the sum of their digits is equal to 9 or a multiple of 9. Numbers are divisible by 10 if the last digit of the number is 0.
There are 5 numbers between 17 and 61 that are divisible by 8. They are 24, 32, 40, 48, and 56.
90
40
125 different 4 digits numbers. To be divisible by 4, the last two digits must be divisible by 4, which means they must be: 12, 24, 32, 44 or 52 - 5 possible choices. For each of these there are 5 choices for the first digit and 5 for the second, meaning: total = 5 x 5 x 5 = 125